add TODO, tests and some small fixes

add TODO
add a bunch of tests
fix issue where 'order by' was being confused with the 'or' operator
  due to bad lexing
fix missing ctor in parens scalar expr parser
rename parens scalar parser to sparens and betweenParens helper to
  parrens
export the makeSelect from the syntax module
add support for count(*)
pretty printer, minor clean ups

clean up some warnings
update the cabal file
add pretty printer
add pretty printing tests
put the modules in a better path
split number literals and string literals
implement complete base 10 number parser, shorten some syntax names
add directions to order by
add support for limit and offset
start work on cast expressions, add lots more test targets
work on errors